The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
A motor vehicle having an automatic transmission includes a control scheme of shift schedule for determining when the automatic transmission shifts from one gear ratio to another gear ratio based on a plurality of factors. These factors typically include, but are not limited to, engine torque, vehicle speed and accelerator pedal position. Any given shift schedule for a motor vehicle balances fuel economy versus performance, and so any given shift schedule may be categorized as an economy shift schedule or a performance shift schedule based on the balance that characterizes the shift schedule.
For a given trip in a motor vehicle, there are times when fuel economy is preferred over high-performance and other times when high-performance is preferred over fuel economy. Accordingly, it is desirable to have the ability to transition between various shift schedules, such as between an economy shift schedule and a performance shift schedule, based on given driving conditions. However, it can be difficult to automatically determine which shifting schedule is desired due to variability in driving conditions, such as road grade, and vehicles parameters, such vehicle mass. Accordingly, the present invention provides a method for selecting a shift schedule using estimated road grade and vehicle mass.